EP3240033B1

EP3240033B1 - Oled array substrate, manufacturing method thereof, packaging structure and display device

Info

Publication number: EP3240033B1
Application number: EP15860030.4A
Authority: EP
Inventors: Liang Sun
Original assignee: BOE Technology Group Co Ltd
Current assignee: BOE Technology Group Co Ltd
Priority date: 2014-12-26
Filing date: 2015-11-17
Publication date: 2022-08-24
Anticipated expiration: 2035-11-17
Also published as: WO2016101731A1; CN104465709B; CN104465709A; EP3240033A4; US20170170423A1; US10205116B2; EP3240033A1

Description

TECHNICAL FIELD

The present disclosure relates to the field of display technology, and in particular to an organic light emitting diode (OLED) array substrate and a method for manufacturing the same, an OLED packaging structure and a display device.

BACKGROUND

OLED apparatus has the advantages such as all-solid-state structure, high brightness, full viewing angle, quick response, wide working temperature range, capable of achieving flexible display, and therefore has become a competitive and promising new generation of display technology. The organic light emitting material and the cathode material of the OLED apparatus are sensitive to moisture and oxygen, a service life of the OLED apparatus may be influenced adversely in a wet or highoxygen-content environment.
In order to prevent moisture and oxygen from influencing adversely the OLED apparatus, the OLED apparatus is required to be packaged. In the process of packaging, the OLED array substrate is adhered to a packaging substrate by a sealant, thereby to form a sealed apparatus structure and block moisture and oxygen in the air. A spacer is arranged between the OLED array substrate and the packaging substrate, so to support them and form a cell gap therebetween.
A top light-emitting OLED apparatus is generally provided with a relative thin cathode so as to achieve a relative high light transmittance. However, a surface of the OLED array substrate is not even, a lap joint of the thin cathode may be poor at an uneven portion of the surface of the OLED array substrate (e.g., where the spacers are located), therefore a cathode resistance may be increased and a power consumption of the OLED array substrate may be increased as a result. Nevertheless, the light transmittance of the OLED array substrate may be decreased and then the display effect may be influenced adversely if the cathode is thick.
CN 104064686 A discloses an organic light-emitting display device. The organic light-emitting display device includes a first substrate, a second substrate, a plurality of organic light-emitting elements and a conductive layer. The first substrate and the second substrate are arranged opposite each other. The organic light-emitting elements are arranged on the side of the first substrate facing the second substrate. Each organic light-emitting element includes an anode arranged on the first substrate, an organic light-emitting layer arranged on the anode and a cathode arranged on the organic light-emitting layer. The conductive layer is arranged on the side of the second substrate facing the first substrate and contacted with the cathodes.
EP 2 182 564 A1 discloses an organic light emitting display device. The organic light emitting display device includes a plurality of light emitting elements on a first substrate, each of the plurality of light emitting elements including a first electrode and an organic light emitting layer, and a second electrode on the plurality of light emitting elements; a second substrate facing the first substrate with the plurality of light emitting elements therebetween; spacers on the second substrate corresponding to portions of the second electrode, the portions located on spaces between the plurality of light emitting elements; and an auxiliary electrode on the spacers and contacting the second electrode.
CN 103943663 A discloses an OLED display device. The OLED display device includes an array substrate and a package substrate which are packaged together. The array substrate includes a first electrode layer, a second electrode layer and a light-emitting function layer located between the first electrode layer and the second electrode layer. The first electrode layer includes a plurality of pixel electrodes which are not contacted with one another. The second electrode layer comprises a plurality of second electrodes which are not contacted with one another, and each second electrode corresponds to at least one pixel electrode. The OLED display device further includes transmission leads, and each transmission lead corresponds to one of the second electrodes so as to input electric signals into the corresponding second electrode.
CN 103022378 A discloses an organic light emitting diode (OLED) and a packaging method. The OLED device includes an array substrate and a packaging substrate. An OLED structure is manufactured on the surface of the array substrate. The edge of the array substrate and the edge of the packaging substrate are bonded and fixed through frame sealing glue. The OLED structure is located between the array substrate and the packaging substrate. A moisture-proof layer used for blocking water vapor and oxygen is manufactured on the surface of the OLED structure. A drying agent layer is located between the moisture-proof layer and the packaging substrate, wherein the drying agent layer includes drying agent particles which are used for absorbing water vapor and oxygen in the OLED device.
US 2001/0043046 A1 provides a luminescent apparatus having a bright, high-quality image. A reflecting surface-including electrode, and an EL element formed of an organic EL layer and a transparent electrode are provided on an insulator. An auxiliary electrode formed of a transparent conductive film is connected to the transparent electrode via a conductor. This structure enables a resistance value of the transparent electrode to be substantially lowered, and a uniform voltage to be applied to the organic EL layer.
US 2014/0062290 A1 provides an organic light emitting display apparatus which includes a substrate, a display portion on the substrate, the display portion including a plurality of emission regions, each including an organic light emitting diode (OLED), and a plurality of non-emission regions protruding from between the plurality of emission regions, an encapsulation substrate facing the substrate, a sealing material bonding the substrate and the encapsulation substrate and sealing the display portion, and a filling material on a surface of the encapsulation substrate facing the display portion, the filling material being spaced apart from the OLED and being formed of a cured polyimide (PI).

SUMMARY

The present disclosure provides an OLED array substrate and a method for manufacturing the same, an OLED packaging structure and a display device, as defined in the accompanying claims, so as to make the lap joint of the cathode firm and reduce the power consumption of the OLED array substrate without reducing the light transmittance of the OLED array substrate. It should be noted that the invention is defined by the attached claims, and any examples and embodiments not covered by these claims are to be understood as aspects contributing to the understanding of the invention.
The surface of the OLED array substrate is not even at the regions of the spacers. According to the embodiments of the present disclosure, the cathodes at the regions where the spacers are located are thickened without changing the thicknesses of the cathodes at the other regions, so as to make the lap joint of the cathode at an uneven portion of the surface of the OLED apparatus firm and reduce the cathode resistance without reducing the light transmittance of the cathodes at the light-emitting regions, thereby to reduce a power consumption of the OLED array substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig.1 is a plan view of an OLED array substrate;
Fig.2 is a sectional view of the OLED array substrate shown in Fig.1 along line B-B';
Fig.3 is an enlarged view of the portion A of the OLED array substrate shown in Fig.2;
Fig.4 is a plan view of an OLED array substrate according to some embodiments of the present disclosure;
Fig.5 is a sectional view of the OLED array substrate shown in Fig.4 along line B-B'; and
Fig.6 is an enlarged view of the portion C of the OLED array substrate shown in Fig.5.

Reference numbers of drawings

11: spacer 12: sub-pixel 13: cathode 14: cathode at a first region 15: pixel definition layer 16: cathode at a second region

DETAILED DESCRIPTION

In order to make the objects, the technical solutions and the advantages of the present disclosure more apparent, the present disclosure will be described hereinafter in conjunction with the drawings and embodiments. Obviously, the following embodiments merely relate to a part of, rather than all of, the embodiments of the present disclosure, and based on these embodiments, a person skilled in the art may, without any creative effort, obtain the other embodiments, which also fall within the scope of the present disclosure.
Unless otherwise defined, any technical or scientific term used herein shall have the common meaning understood by a person of ordinary skills. Such words as "first" and "second" used in the specification and claims are merely used to differentiate different components rather than to represent any order, number or importance. Similarly, such words as "one" or "one of' are merely used to represent the existence of at least one member, rather than to limit the number thereof. Such words as "connect" or "connected to" may include electrical connection, direct or indirect, rather than to be limited to physical or mechanical connection. Such words as "on", "under", "left" and "right" are merely used to represent relative position relationship, and when an absolute position of the object is changed, the relative position relationship will be changed too.
The present disclosure provides in some embodiments an OLED array substrate and a method for manufacturing the same, an OLED packaging structure and a display device, so as to make the lap joint of the cathode firm and reduce the power consumption of the OLED array substrate without reducing the light transmittance of the OLED array substrate.
Fig.1 is a plan view of an OLED array substrate. Fig.2 is a sectional view of the OLED array substrate shown in Fig.1 along Line B-B'. Fig.3 is an enlarged view of the portion A of the OLED array substrate shown in Fig.2.
Thin film transistors, pixel definition layers, anodes, organic functional layers and cathodes are formed on the OLED array substrate. The pixel definition layer defines a plurality of sub-pixels 12. A top light-emitting OLED apparatus is generally provided with relative thin cathodes 13 so as to achieve a relative high light transmittance. However, the OLED array substrate need to be packaged with a packaging substrate, so spacers 11 are needed to be arranged between the OLED array substrate and the packaging substrate to support them and then form a cell gap therebetween. Each spacer 11 includes a planarization layer resin and a pixel definition layer resin formed in advance of the cathodes. The cathodes 13 cover the spacers 11. Each spacer 11 is of a certain thickness, so the surface of the OLED array substrate is uneven at the regions where the spacers 11 are located and nearby. As shown in Fig.3, a lap joint of a relative thin cathode may be poor at each spacer 11, and then a resistance of each cathode 13 may be increased and a power consumption of the OLED array substrate may be increased as a result. Nevertheless, the light transmittance of the OLED array substrate may be decreased and then the display effect may be influenced adversely if the cathode is thick.
In view of this, an OLED array substrate is provided in some embodiments of the present disclosure, including thin film transistors, anodes, cathodes and organic light-emitting layers arranged between the anodes and the cathodes. The OLED array substrate further includes first spacers configured to support the OLED array substrate and a packaging substrate so as to form a cell gap therebetween. Each cathode includes a first region which covers the corresponding first spacer and a second region beyond the first regions, and a thickness of the cathode at the first region is larger than a thickness of the cathode at the second region.
The surface of the OLED array substrate is not even at the regions where the spacers are located. According to the present disclosure, the cathodes at the regions where the spacers are located are thickened without changing the thicknesses of the cathodes at the other regions, so as to make the lap joint of the cathode at an uneven portion of the surface of the OLED apparatus firm and reduce the cathode resistance without reducing the light transmittance of the cathodes at the light-emitting regions, thereby to reduce a power consumption of the OLED array substrate.
Fig.4 is a plan view of an OLED array substrate according to some embodiments of the present disclosure. Fig.5 is a sectional view of the OLED array substrate shown in Fig.4 along Line B-B'. Fig.6 is an enlarged view of the portion C of the OLED array substrate shown in Fig.5. As shown in Figs.5 and 6, each cathode of the OLED array substrate includes a first region which covers the corresponding first spacer 11 and a second region beyond the first regions, and a thickness of the cathode 14 at the first region is larger than a thickness of the cathode 16 at the second region.
Furthermore, the cathodes 14 at the first regions are of an identical thickness, and the cathodes16 at the second regions are of an identical thickness. To be specific, the cathode 14 at each first region is of a thickness larger than the cathode 16 at each second region by 1 to 20 nanometers. In some embodiments of the present disclosure, only a part of each cathodes are thickened, so as to make the lap joint of the cathode at an uneven portion of the surface of the OLED apparatus firm and reduce the cathode resistance without influencing adversely the light transmittance of the cathodes at the light-emitting regions, thereby to reduce a power consumption of the OLED array substrate.
An OLED packaging structure is further provided in some embodiments of the present disclosure, including the OLED array substrate hereinabove and a packaging substrate.
An edge of the OLED array substrate is adhered to an edge of the packaging substrate by a sealant. The OLED packaging structure further includes second spacers configured to support the OLED array substrate and the packaging substrate so as to form a cell gap therebetween. The second spacers are arranged in the sealant.
Each spacer is of a certain thickness, so the surface of the OLED array substrate is not even at the regions where the spacers are located. According to the embodiments of the present disclosure, the cathodes at the regions where the spacers are located are thickened without changing the thicknesses of the cathodes at the other regions, so as to make the lap joint of the cathode at an uneven portion of the surface of the OLED apparatus firm and reduce the cathode resistance without reducing the light transmittance of the cathodes at the light-emitting regions, thereby to reduce a power consumption of the OLED array substrate.
A display device is further provided in some embodiments of the present disclosure, including the OLED packaging structure hereinabove. The display device may be any product or component with a display function such as cell phones, tablet PCs, televisions, displayers, laptop computers, digital frames and navigators.
Fig.1 is a plan view of an OLED array substrate. Fig.2 is a sectional view of the OLED array substrate shown in Fig.1 along Line B-B'. Fig.3 is an enlarged view of the portion A of the OLED array substrate shown in Fig.2.
Thin film transistors, pixel definition layers, anodes, organic functional layers and cathodes are formed on the OLED array substrate. The pixel definition layer defines a plurality of sub-pixels 12. A top light-emitting OLED apparatus is generally provided with relative thin cathodes 13 so as to achieve a relative high light transmittance. However, the OLED array substrate need to be packaged with a packaging substrate, so spacers 11 are arranged between the OLED array substrate and the packaging substrate to support them and then form a cell gap therebetween. Each spacer 11 includes a planarization layer resin and a pixel definition layer resin formed in advance of the cathodes. The cathodes 13 cover the spacers 11. Each spacer 11 is of a certain thickness, so the surface of the OLED array substrate is uneven at the regions where the spacers 11 are located. As shown in Fig.3, a lap joint of a relative thin cathode may be poor at each spacer 11, and then a resistance of each cathode 13 may be increased and a power consumption of the OLED array substrate may be increased as a result. Nevertheless, the light transmittance of the OLED array substrate may be decreased and then the display effect may be influenced adversely if the cathode is thick.
In view of this, a method for manufacturing an OLED array substrate is further provided. The OLED array substrate includes thin film transistors, anodes, cathodes and organic light-emitting layers arranged between the anodes and the cathodes. The OLED array substrate further includes spacers configured to support the OLED array substrate and a packaging substrate so as to form a cell gap therebetween. The method includes forming the cathodes on a substrate provided with the spacers, the thin film transistors, the anodes and the organic light-emitting layers, wherein each cathode includes a first region which covers the corresponding spacer and a second region beyond the first region, a thickness of the cathode at each first region is larger than a thickness of the cathode at each second region.
Fig.4 is a plan view of an OLED array substrate according to some embodiments of the present disclosure. Fig.5 is a sectional view of the OLED array substrate shown in Fig.4 along Line B-B'. Fig.6 is an enlarged view of the portion C of the OLED array substrate shown in Fig.5. As shown in Figs.5 and 6, each cathode of the OLED array substrate includes a first region which covers the corresponding first spacer 11 and a second region beyond the first regions, and a thickness of the cathode 14 at the first region is larger than a thickness of the cathode 16 at the second region.
Furthermore, the cathodes 14 at the first regions are of an identical thickness, and the cathodes 16 at the second regions are of an identical thickness. To be specific, the cathode 14 at each first region is of a thickness larger than the cathode 16 at each second region by 1 to 20 nanometers.
Furthermore, the step of forming the cathodes includes forming a first cathode pattern corresponding to the first regions and the second regions on the substrate provided with the spacers, the thin film transistors, the anodes and the organic light-emitting layers; and forming, on the first cathode pattern, a second cathode pattern corresponding to the first regions, wherein the cathodes are formed by the first and the second cathode patterns.
As compared with the second regions, the first regions further include a second cathode pattern, so the cathode at each first region is of a thickness larger than the cathode at each second region.
To be specific, the second cathode pattern may be formed on substrate arranged with the first cathode pattern by evaporation. The step of forming, on the first cathode pattern, the second cathode pattern corresponding to the first regions includes attaching the substrate provided with the first cathode pattern and an evaporation mask closely, the evaporation mask including openings corresponding to the first regions; and forming the second cathode pattern on the substrate through evaporation using a cathode evaporating source arranged opposite to the evaporation mask.
In some embodiments of the present disclosure, only a part of each cathodes is thickened, so as to make the lap joint of the cathode at an uneven portion of the surface of the OLED apparatus firm and reduce the cathode resistance without influencing adversely the light transmittance of the cathodes at the light-emitting regions, thereby to reduce a power consumption of the OLED array substrate.
The above are merely the preferred embodiments of the present disclosure.

Claims

An organic light emitting diode (OLED) array substrate, comprising:
thin film transistors, anodes, cathodes (13) and organic light-emitting layers arranged between the anodes and the cathodes (13), wherein the OLED array substrate further comprises first spacers (11) configured to support the OLED array substrate and a packaging substrate so as to form a cell gap therebetween,

each cathode (13) comprises a first region (14) which covers the corresponding first spacer (11) and a second region (16) beyond the first regions (14), and a thickness of the cathode (13) at the first region (14) is larger than a thickness of the cathode (13) at the second region (16),

a projection of the first region (14) on the array substrate completely covers a projection of the corresponding first spacer (11) on the array substrate, and the cathodes (13) at the first regions (14) are of an identical thickness, the cathodes (13) at the second regions (16) are of an identical thickness,

characterized in that

the cathode (13) at each first region (14) is of a thickness larger than the cathode (13) at each second region (16) by 1 to 20 nanometers.
An organic light emitting diode (OLED) packaging structure, comprising the OLED array substrate according to claim 1 and a packaging substrate.
The OLED packaging structure according to claim 2, wherein an edge of the OLED array substrate is adhered to an edge of the packaging substrate by a sealant.
The OLED packaging structure according to claim 3, further comprising:
second spacers configured to support the OLED array substrate and the packaging substrate so as to form a cell gap therebetween, the second spacers being arranged in the sealant.
A display device, characterized in that the display device comprises the OLED packaging structure according to any one of claims 2-4.
A method for manufacturing an organic light emitting diode (OLED) array substrate, wherein the OLED array substrate comprises thin film transistors, anodes, cathodes (13) and organic light-emitting layers arranged between the anodes and the cathodes (13), the OLED array substrate further comprises spacers (11) configured to support the OLED array substrate and a packaging substrate so as to form a cell gap therebetween,
the method comprises:
forming the cathodes (13) on a substrate provided with the spacers (11), the thin film transistors, the anodes and the organic light-emitting layers, wherein each cathode (13) comprises a first region (14) which covers the corresponding spacer (11) and a second region (16) beyond the first region (14), a thickness of the cathode (13) at each first region (14) is larger than a thickness of the cathode (13) at each second region (16),

a projection of the first region (14) on the array substrate completely covers a projection of the corresponding spacer (11) on the array substrate, and the cathodes (13) at the first regions (14) are of an identical thickness,

the cathodes (13) at the second regions (16) are of an identical thickness,

characterized in that

the cathode (13) at each first region (14) is of a thickness larger than the cathode (13) at each second region (16) by 1 to 20 nanometers.
The method according to claim 6, wherein the step of forming the cathodes (13) comprises:
forming a first cathode pattern corresponding to the first regions (14) and the second regions (16) on the substrate provided with the spacers (11), the thin film transistors, the anodes and the organic light-emitting layers; and

forming, on the first cathode pattern, a second cathode pattern corresponding to the first regions (14), wherein the cathodes (13) are formed by the first and the second cathode patterns.
The method according to claim 7, wherein the step of forming, on the first cathode pattern, the second cathode pattern corresponding to the first regions (14) comprises:
attaching the substrate provided with the first cathode pattern and an evaporation mask closely, the evaporation mask comprising openings corresponding to the first regions (14); and

forming the second cathode pattern on the substrate through evaporation using a cathode evaporating source arranged opposite to the evaporation mask.